A man accused of stabbing another man in a car park brawl - inflicting a 20-centimetre gash from chest to back - has been found not guilty.

An ACT Supreme Court jury on Tuesday took six hours to acquit Jesse Roland Palmer of intentionally inflicting grievous bodily harm.

He was also cleared of an alternate count of recklessly inflicting grievous bodily harm.

In light of the verdict, Justice Hilary Penfold also dismissed the summary charge of possessing a knife without a reasonable excuse.

Mr Palmer and the complainant were both drinking at the Belconnen Soccer Club in Hawker in December 2010.

The court heard Mr Palmer had been asked to leave the premises after abusing a staff member.

Outside he asked the complainant's brother, ''What are you looking at?'' and pulled a knife when the man confronted him.

The man then rang the complainant for back-up.

In the ensuing brawl, the complainant received a 20-centimetre slash from his chest, under his left arm and into his back.

He was taken to hospital and required surgery the following day.

Both legal teams completed closing submissions on Friday.

The Crown argued Mr Palmer had been aggressive inside the club and was looking for a fight.

Prosecutor Amanda Clarke said Mr Palmer had finished what he started.

But the accused man's barrister argued his client had not deliberately caused the injury.

In the witness box, Mr Palmer said he used a knife in his work as a plumber and had it with him because he had forgotten to remove it from his pants after being on the job that day.

Mr Palmer said he did not want to fight and the complainant had punched both himself and his brother.

He said the injury was sustained as the complainant attacked him.

In dismissing the summary charge, Justice Penfold accepted Mr Palmer's account of why the knife had been in his possession.

''I cannot see a basis for a finding of guilt,'' Justice Penfold said. ''If there were an offence for stupidly pulling a knife … Mr Palmer would be guilty.''